The air delivery is controlled by electronic actuators
mounted on the HVAC module. The actuators are controlled by the heater and
A/C control. Each actuator responds to voltage inputs on the motor control
circuit with precalibrated non-adjustable position settings. The heater and
A/C control adjusts the actuators to obtain, condition and discharge the air
as requested by the operator of the vehicle. There are three actuators, air
inlet, mode and air mix:
| • | The air inlet actuator controls the outside/recirc door position.
There are only two positions of operation for the air inlet actuator. The
heater and A/C control commands the air inlet actuator to provide either outside
or recirculated air to the inlet of the HVAC module. |
| • | The air mix actuator controls the amount of air that flows around
or through the heater core. The heater and A/C control can command the air
mix actuator to any one of 21 door positions from full heat to full by-pass. |
| • | The air discharge is controlled by the mode door actuator. The
actuator drives a cam wheel that controls the position or the two air discharge
doors. The heater and A/C control can command the mode door actuator to any
one of 5 positions. |
